Protective enclosure for an interactive flat-panel controlled device

ABSTRACT

A protective enclosure is disclosed for an interactive flat-panel controlled device. The protective enclosure is watertight, crush-resistant, and impact-resistant. While providing protection, the protective enclosure simultaneously allows smooth and accurate interaction with the interactive flat-panel controlled device. The protective enclosure has a protective membrane that permits RF and touch screen stylus inputs, as well as capacitance, such as from a finger, to be transmitted accurately to the flat-panel control. The hardness and texture of the protective membrane allows a stylus or finger to glide smoothly along the surface of the membrane without catching or sticking. The protective enclosure is further adapted to allow infrared and other communication signals while the device is secured inside the case. Further, electrical connections can be made through the case without affecting the protection afforded the electronic device inside.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part of U.S. patent applicationSer. No. 10/645,439 entitled “Protective Membrane for Touch ScreenDevice” by Curtis R. Richardson, filed Aug. 20, 2003.

United State patent application Ser. No. 10/645,439 is a continuation ofUnited State patent application Ser. No. 10/300,200 entitled “ProtectiveCase for Touch Screen Device” by Curtis R. Richardson, filed Nov. 19,2002, which claims the benefit of and priority to U.S. ProvisionalPatent Application Ser. No. 60/335,865 filed Nov. 19, 2001 by Curtis R.Richardson entitled “Protective Case for Touch Screen Device.” Theentire contents of the above mentioned applications are herebyspecifically incorporated herein by reference for all they disclose andteach.

BACKGROUND OF THE INVENTION

a. Field of the Invention

The present invention pertains generally to protective cases andspecifically to protective cases for devices that have an interactiveflat-panel control.

b. Description of the Background

Personal Digital Assistants, or PDAs as well as other portableelectronic devices are being very widely used, and are being deployed inindustrial as well as office environments. PDAs are being used inindustrial environments for data collection, such as service informationon an airplane, or for data delivery such as maps for fire fighters andother emergency personnel. When PDAs are deployed in such industrialapplications, the data that is collected and displayed on the PDA can beextremely valuable and can be life saving.

The industrial environments impose harsh conditions that typical PDAsare not designed to accommodate. For example, damage can be done to thePDA through rough handling and dropping. Further, industrial chemicals,grease, water, dirt, and grime may damage or destroy a functioning PDAand inhibit the use of the PDAs valuable data.

It is common to hold the PDAs inside a protective case for transport.However, in the case of a firefighter using the PDA on a fire scene,opening a case with gloved hands in the midst of fighting a fire exposesthe PDA to easily being dropped, getting wet, or otherwise beingdamaged.

The user interface for PDAs is typically a few buttons and a touchscreen display. The touch screen is used to both display information andto capture information. The data capture generally uses a stylus toselect buttons or areas on the screen for certain functions, draw shapesonto the screen, use character recognition to enter text or numbers, orother methods of data capture.

The PDA may be connected to another computer by several mechanisms. ThePDA may be direct connected using a wire connection, wherein a cablewith a connector physically connects to the PDA. A second method is touse an infrared communication protocol that uses an infrared transmitterand receiver mounted in the PDA to communicate with another computerhaving a similar transceiver. A third method is to communicate via radiosignals such as a cellular phone protocol or wireless modem.

It would therefore be advantageous to provide a case for a PDA whereinthe PDA may be fully operated when the PDA is stored securely in thecase. Further, the operation of the PDA through its touch screeninterface should not be hindered by a protective case. The case wouldalso not interfere with the connections between the PDA and anothercomputer.

SUMMARY OF THE INVENTION

The present invention overcomes the disadvantages and limitations of theprior art by providing a watertight, crush-resistant, and impactresistant protective enclosure that protects a devices that has aninteractive flat-panel control and simultaneously permits smooth andaccurate interactive use of the flat-panel control.

The present invention may therefore comprise a protective enclosure fora tablet PC having an interactive flat-panel control comprising: a shellthat is capable of enclosing the tablet PC, the tablet PC being aseparate unit from the protective enclosure, the tablet PC beinginsertable in and removable from the enclosure by hand, the shell beingsubstantially crush-resistant and having an elevated protective rimaround a perimeter portion of the interactive flat-panel control of thetablet PC so that when the tablet PC is disposed in the enclosure, theinteractive flat-panel control of the tablet PC is recessed with respectto the protective rim of the shell so that the elevated protective rimprotects the interactive flat-panel control from breakage; and aprotective membrane that is integrally fixed to a shock-absorbingcushion, the shock-absorbing cushion being fixed to the shell, theshock-absorbing cushion forming a seal between the shell and theprotective membrane so that the protective enclosure is substantiallywatertight, the protective membrane is disposed over the interactiveflat-panel control of the tablet PC when the tablet PC is disposed inthe enclosure, the protective membrane having a back side that has asubstantially planar smooth surface that is adjacent to the interactiveflat-panel control of the tablet when the tablet PC is disposed in theenclosure so that inputs on a front side of the protective membrane arecommunicated to the interactive flat-panel control through theprotective membrane, the protective membrane being at least partiallytransparent such that the interactive flat-panel control is visiblethrough the protective membrane, the shock-absorbing cushion pressingthe protective membrane flatly against the interactive flat-panelcontrol of the tablet PC so that smooth stylus strokes and inputs may betransmitted accurately to the interactive flat-panel control.

The present invention may further comprise a protective enclosure for ahandheld device having a capacitance-sensing interactive flat-panelcontrol comprising: a shell that is capable of enclosing the handhelddevice, the handheld device being a separate unit from the protectiveenclosure, the handheld device being insertable in and removable fromthe enclosure by hand, the shell being substantially crush-resistant andhaving an elevated protective rim around a perimeter portion of thecapacitance-sensing interactive flat-panel control of the handhelddevice so that when the handheld device is disposed in the enclosure,the capacitance-sensing interactive flat-panel controlled device of saidtablet is recessed with respect to said protective rim of said shell sothat said elevated protective rim protects the interactive flat-panelcontrol from breakage; and a protective membrane that is integrallyfixed to the shell, the protective membrane disposed over thecapacitance-sensing interactive flat-panel control of the handhelddevice when the handheld device is disposed in the enclosure, theprotective membrane having a back side that has a substantially planarsmooth surface that is adjacent to the capacitance-sensing interactiveflat-panel control of the handheld device when the handheld device isdisposed in the enclosure, the protective membrane being sufficientlythin that capacitive inputs on a front side of the protective membraneare transmitted to the capacitive-sensing interactive flat-panel controlthrough the protective membrane, the protective membrane being at leastpartially transparent such that the interactive flat-panel control isvisible through the protective membrane, the protective membrane havinga dielectric constant such that capacitive inputs on a front side of theprotective membrane are transmitted to the capacitance-sensinginteractive flat-panel control.

The invention may further comprise a method of manufacturing aprotective enclosure for a device having an interactive flat-panelcontrol comprising: providing a protective shell that is crush resistantand impact resistant, the protective shell having embedded stiffenersthat prevent the protective shell from warping, the protective shellthat is adapted to enclose a device having an interactive flat-panelcontrol, the device being a separate unit from the protective enclosure,the device being insertable in and removable from the shell by hand, theshell being substantially crush-resistant and providing an elevatedprotective rim around a perimeter portion of the interactive flat-panelcontrol of the device so that when the device is disposed in theenclosure, the interactive flat-panel control is recessed with respectto the protective rim of the shell so that the elevated protective rimprotects the interactive flat-panel control of the device from breakage;providing a protective membrane that is capable of being integrallyfixed on the shell so that the protective membrane is disposed over theinteractive flat-panel control of the device when the device is disposedin the enclosure, the protective membrane having a back side that has asubstantially planar smooth surface adjacent the interactive flat-panelcontrol when the device is disposed in the enclosure so that inputs on afront side of the protective membrane are communicated to theinteractive flat-panel control through the protective membrane, theprotective membrane being at least partially transparent such that theinteractive flat-panel control is visible through the protectivemembrane; and fixing the protective membrane onto the protective shellso that the protective membrane and the protective shell form aprotective enclosure for the touch screen device.

The invention may further comprise a method of manufacturing aprotective enclosure for a device having a capacitance-sensinginteractive flat-panel control comprising: providing a protective shellthat is crush-resistant and impact-resistant, the protective shell thatis adapted to enclose a device having a capacitance-sensing interactiveflat-panel control, the device being a separate unit from the protectiveenclosure, the device being insertable in and removable from the shellby hand, the shell being substantially crush-resistant and providing anelevated protective rim around a perimeter portion of thecapacitance-sensing interactive flat-panel control of the device so thatwhen the device is disposed in the enclosure, the capacitance-sensinginteractive flat-panel control is recessed with respect to theprotective rim of the shell so that the elevated protective rim protectsthe capacitance-sensing interactive flat-panel control of the devicefrom breakage; providing a protective membrane that is capable of beingintegrally fixed on the shell so that the protective membrane isdisposed over the capacitance-sensing interactive flat-panel control ofthe device when the device is disposed in the enclosure, the protectivemembrane having a back side that has a substantially planar smoothsurface adjacent the interactive flat-panel control when the device isdisposed in the enclosure, the protective membrane being sufficientlythin and having dielectric constant so that capacitive inputs on a frontside of the protective membrane are communicated to thecapacitance-sensing interactive flat-panel control through theprotective membrane, the protective membrane being at least partiallytransparent such that the capacitance-sensing interactive flat-panelcontrol is visible through the protective membrane; and fixing theprotective membrane onto the protective shell so that the protectivemembrane and the protective shell form a protective enclosure for thedevice.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings,

FIG. 1 is a perspective view of an embodiment of the invention shown inthe closed position.

FIG. 2 is a perspective view of an embodiment of the invention shown inthe open position.

FIG. 3 is a perspective view of an embodiment of the invention shown inan exploded state.

FIG. 4 is a perspective view of an embodiment of the invention shownfrom the rear.

FIG. 5 is a front view of an embodiment of the invention, showing asection line.

FIG. 6 is a section view of an embodiment of the invention.

FIG. 7 is a detailed view of a section shown in FIG. 6.

FIG. 8 is a perspective view of another embodiment comprising a singlepiece encapsulating cover.

FIG. 9 is a perspective view of a third embodiment comprising anon-encapsulating snap over cover.

FIG. 10 is a perspective view of an embodiment that comprises a beltclip.

FIG. 11 is a second perspective view of an embodiment that comprises abelt clip.

FIG. 12 is a perspective view of another embodiment of the presentinvention of a protective cover for a PDA or other device.

FIG. 13A is a perspective top view of another embodiment of a protectiveenclosure for a tablet PC.

FIG. 13B is a view of the protective enclosure lid of FIG. 13A.

FIG. 14 is a perspective top view of the embodiment of FIG. 13A with anopen lid.

FIG. 15 is a perspective bottom view of the embodiment of FIG. 13A.

FIG. 16 is a perspective view of the base of the embodiment of FIG. 13AFIG. 17 is an exploded view of an embodiment of a protective enclosurefor an interactive flat-panel controlled device.

FIG. 18 is an exploded view of another embodiment of a protectiveenclosure for an interactive flat-panel controlled device.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 is a perspective view of an embodiment of the invention.Embodiment 100 comprises a rigidly molded front case 102 and rear case104. An overmolded grommet 106 forms a receptacle for stylus 108 andalso aids in sealing membrane 110. A flexible hand strap 112 attaches tothe rear case 104. A hinge 114 joins front case 102 and rear case 104. Aring 124 for a lanyard is shown as an integral feature of rear case 104.

Embodiment 100 is designed to hold a conventional personal digitalassistant (PDA) in a protective case. A PDA, such as a Palm Pilot,Handspring Visor, Compaq Ipaq, Hewlett Packard Jornada, or similarproducts use a touch screen for display and data entry. The touch screendisplay comprises either a color or black and white liquid crystaldisplay with a touch sensitive device mounted on top of the display. Thedisplay is used for displaying graphics, text, and other elements to theuser. The touch screen is used with a stylus 108 to select elements fromthe screen, to draw figures, and to enter text with a characterrecognition program in the PDA. The stylus 108 generally resembles aconventional writing implement. However, the tip of the writingimplement is a rounded plastic tip. In place of a stylus 108, the usermay use the tip of a finger or fingernail, or a conventional pen orpencil. When a conventional writing implement is used, damage to thetouch screen element may occur, such as scratches.

For the purposes of this specification, the term PDA shall include anyelectronic device that has a touch screen interface. This may includeinstruments such as voltmeters, oscilloscopes, logic analyzers, and anyother hand held, bench top, or rack mounted instrument that has a touchscreen interface. Hand held devices, such as cell phones, satellitephones, telemetric devices, and other hand held devices are also to beclassified as PDAs for the purposes of this specification. The term PDAshall also include any computer terminal display that has a touch screeninterface. These may comprise kiosks, outdoor terminal interfaces,industrial computer interfaces, commercial computer interfaces and othercomputer displays. Additionally, the term PDA may comprise barcodescanners, hand held GPS receivers, and other handheld electronicdevices. The foregoing description of the term PDA has been presentedfor purposes of illustration and description. It is not intended to beexhaustive or to limit the invention to the precise forms disclosed, andother modifications and variations may be possible in light of theteachings of this specification.

In addition, the PDAs typically have a handful of additional buttons aspart of the user interface. These buttons are generally on the front ofthe device, near the touch screen element. The additional buttons may beused as shortcut buttons to instantly call up a certain program on thePDA, may comprise a method of scrolling, may be used to select itemsfrom a list, or may have any function that the designer of the PDAsoftware may assign to the button or set of buttons. The button size,layout, and function may vary for each manufacturer and model of PDA.

Further, PDAs typically have at least one method of connecting toanother computer. This may be through a direct electrical connection,such as through a wire cable or fiber optic, or through another mediumsuch as infrared communication or through a radio communication.

Additionally, the PDAs typically have an electrical source. Theelectrical source may be a rechargeable or non-rechargeable battery orsolar cells. The electrical source may be a remote source of electricitythat is transmitted to the PDA through a wire cable or through othermethods of electrical transmission.

Further, PDAs may have indicator lights, such as status lights forpower, communication, battery status, or other functions. The lights maybe located on any of the sides of the PDA and may be viewable on one ormore sides.

Front case 102 and rear case 104 form a protective cover for the PDA.The protective cover may be designed for rugged industrial use,recreational use, commercial use, or many other uses. An industrial usemay require the protective cover to be watertight, chemically resistant,protect the unit when dropped, and be crush proof. A typical applicationmay be for fire fighters to use a PDA for a display of maps fordirections to an emergency scene or for a building plan at the scene ofa fire. Another example may be a maintenance mechanic in a chemicalplant using a PDA to record maintenance records in the plant thatprocesses. A recreational use may require the cover to be watertight,afford some protection against dropping and being crushed, float inwater, and be dust resistant. A recreational use may be to take the PDAduring kayaking, diving, or other water sport activity. Further, thecase may be used when the PDA is taken camping, hiking, or other outdooractivity. A commercial use may additionally require the protective coverto be elegant, but may also require the cover to be replaceable so thatscratches and other signs of wear and tear can be easily and cheaplyreplaced.

The protective cover for the PDA may take on many embodiments. Theembodiment 100 comprises a front case 102 and rear case 104 that arejoined by a hinge 114 and a clasp mechanism that is on the side of thecases opposite the hinge 114. Other embodiments may have a small doorinto which the PDA slides, or the protective cover may not completelyenclose the PDA and only cover the face where the user interface exists,leaving one or more sides of the PDA exposed. Those skilled in the artmay use other designs of protective covers without deviating from thescope and intent of the present invention.

The protective cover may be constructed of rigid plastic, metal,flexible rubber, or any other type of material that could be adapted toafford the protection of the PDA desired for the application. Forexample, a metal cover may be used in an application where an elegantstyle is necessary but watertightness is not. A flexible rubber covermay be selected for an application in a wet environment. A rigid plasticcover may be selected for an application where dropping the PDA is aconcern. Those skilled in the art may use other types of materials andconstructions without deviating from the spirit of the presentinvention.

The PDA may be mounted in the protective cover using many differentmounting techniques. For example, the PDA may be mounted using open orclosed cell foam inserts in the protective cover. In another embodiment,the PDA may be mounted by attaching the PDA to the cover with afastener. In another embodiment, the PDA may be mounted by snapping intothe protective waterproof cover. In another embodiment, the PDA may beheld in place by resting in molded features of two halves of aprotective case that clamps onto the PDA. Those skilled in the art mayuse other types of locating and holding mechanisms without deviatingfrom the spirit of the present invention.

The overmolded grommet 106 of the present embodiment is constructed byinjection molding a thermoplastic polymerized rubber (TPR) over thefront case 102. The grommet 106 has molded features 116 and 118 adaptedto retain the stylus 108. Features 116 and 118 capture the stylus 108during transportation, but allow the user to remove the stylus 108 tooperate the PDA. In other embodiments of the present invention, thestylus 108 may be constrained to the PDA with a tether or lanyard, orthe constraining features may be incorporated into other components thatmake up the protective cover. Further, the stylus 108 may not be presentin the embodiment, rather, the PDA be adapted to be used with the user'sfingernail or with another implement similar to the stylus 108.

The membrane 110 of the present embodiment is constructed bythermoforming a sheet of thin plastic. The plastic is selected to bethin enough that the deformation of a stylus conducts the touch to thetouch screen, but thick enough to have enough rigidity that the stylusdoes not catch and rip the membrane. Additionally, the membrane 110should have enough thickness to endure scratches and other wear and tearwithout breaking and sacrificing the protective function.Polyvinylchloride material at 0.010in to 0.015in thickness givesacceptable results. Alternatively, membrane 110 may be constructed byinjection molding or other methods. Alternative materials may be used bythose skilled in the art to achieve the same results while maintainingwithin the spirit and intent of the present invention.

The membrane 110 in the present embodiment may be translucent or atleast partially transparent, so that the images displayed on the PDA maybe visible through the membrane 110. The membrane 110 may be tinted orcolorized in some applications. For example, a protective cover designedas a decorative cover may incorporate a colorized membrane 110. Further,the membrane may be selectively colorized and the opaqueness may vary.For example, the protective membrane may be printed or painted in theareas not used for the touch screen. A printing process may incorporatea logo, graphics, or labeling for individual buttons for the PDA. Theprinting process may further incorporate features, such as text orgraphics, that are used by the software on the PDA for a purpose such assimplifying data input or for designating an area on the touch screenfor a specific function, such as a help function. The printing orpainting processes used on the membrane 110 may be purely decorative andmay be for aesthetic purposes only. The printing process may alsocomprise logos or graphics for the brand identity of the PDA cover.Other processes, such as colorizing the raw material for the membrane110 or adding other components to the raw material, such as metal flakesor other additives, may be used to change the optical features of themembrane 110.

The optical performance of the membrane 110 may be changed or enhancedby changing the texture of the area of the touch screen. For example,the membrane may be frosted on the outside to hide scratches or may beimprinted with a lens or other features that change the opticalcharacteristics of the membrane 110. The membrane 110 may have opticalfeatures that are used in conjunction with the software of the PDA. Forexample, all or a portion of the membrane may comprise a lens thatmagnifies an image to a user. When the user touches the image on themembrane 110 and the touch is transferred to the touch screen, thesoftware in the PDA may have to compensate for the positionaldifferences between the image and actual area that was touched by theuser. In another example, if a specific portion of the membrane 110 hada specific optical characteristic, the software of the PDA may beconstructed to display a specific graphic for the area for an intendedeffect.

The membrane 110 in the present embodiment has a recessed portion 120and a raised portion 122. The recessed portion 120 may be adapted topress flat against the touch screen area of a specific PDA. The raisedportion 122 may be adapted to fit over an area of the specific PDA whereseveral buttons are located.

The raised portion 122 allows the user to operate the buttons on thePDA. The raised portion 122 is adapted such that the buttons on the PDAare easily operated through the protective membrane 110. The raisedportion 122 may have special features to aid the user in pressing thebuttons. For example, the raised portion 122 may comprise a dimpled areafor the user's finger located directly over the button. Further, afeature to aid the user may comprise a section of membrane 110 definedby a thinner area around the section, enabling the user to more easilydeflect the section of membrane over the button. The area of thinnermaterial may comprise a large section or a thin line. Further, tactileelements, such as small ribs or bumps may be incorporated into themembrane 110 in the area of the buttons so that the user has a tactilesensation that the user's finger is over the button. The tactile elementmay be particularly effective if the button was a power switch, forexample, that turned on the PDA.

The configuration of the membrane 110 may be unique to each style ormodel of PDA, however, the front case 102 and rear case 104 may be usedover a variety of PDAs. In the present embodiment, the changeover fromone PDA variety to another is accomplished by replacing the membrane 110without having to change any other parts. The present embodiment maytherefore be mass-produced with the only customizable area being themembrane 110 to allow different models of PDAs to be used with a certainfront case 102 and rear case 104.

The hand strap 112 in the present embodiment allows the user to hold theembodiment 100 securely in his hand while using the PDA. The hand strap112 may be constructed of a flexible material, such as rubber or clothwebbing, and may have an adjustment, such as a buckle, hook and loopfastener, or other method of adjustment. In other embodiments, a handstrap may be a rigid plastic handle, a folding handle, or any othermethod of assisting the user in holding the embodiment. Further, theembodiment may be adapted to be fix-mounted to another object, like apiece of machinery, a wall, or any other object. A fix-mountedembodiment may have other accoutrements adapted for a fixed mountapplications, such as receptacles for a stylus adapted to a fix-mount,specialized electrical connections, features for locking the PDA insidethe case to prevent theft, or designs specifically adapted to shed waterwhen rained upon.

FIG. 2 illustrates a perspective view of the embodiment 100 shown in anopen position. The front case 102 and rear case 104 are shown open aboutthe hinge 114. Membrane 110 is shown installed into gasket 106, and therecessed portion 120 and raised portion 122 of membrane 110 isillustrated looking from the inside of the case. The clasp mechanismsare not shown in this illustration. Hand strap 112 is shown attached torear case 104.

FIG. 3 illustrates a perspective view of the embodiment 100 shown in anexploded state. The hand strap 116 attaches to the rear cover 104. Theovermolded grommet 106 holds the stylus 108 and is attached to frontcover 102. The membrane 110 attaches to the grommet 106 and is held inplace with an o-ring 302.

FIG. 4 illustrates a perspective view of the embodiment 100 shown fromthe rear. The hand strap 116 is shown, along with rear cover 104 andfront cover 102. The stylus 108 is shown inserted into the overmoldedgrommet 106.

FIG. 5 illustrates a top view of the embodiment 100. The front cover102, membrane 110, stylus 108, and hinge 114 are all visible.

FIG. 6 illustrates a section view of the embodiment 100 taken throughthe section line shown in FIG. 5. The front cover 102, rear cover 104,overmolded gasket 106, stylus 108, membrane 110, hand strap 112, ando-ring 302 are all shown hatched in this view.

FIG. 7 illustrates a detail view of the embodiment 100 shown in FIG. 6.Front case 102 and rear case 104 are joined at hinge 114. Overmoldedgasket 106 traps membrane 110 and o-ring 302 locks membrane 110 inplace. Overmolded gasket 106 may be formed by molding thermoplasticpolymerized rubber over the front cover 102.

The replacement of the membrane 110 is accomplished by removing o-ring302, pushing the membrane 110 from the overmolded gasket 106, snapping anew membrane 110 into place, and replacing the o-ring 302. The ease ofreplacement of the present embodiment allows a user to quickly replace adamaged membrane 110, allows a user to upgrade their case to a newermodel PDA, and may allow a user to select from various membranes 110 forthe particular application. One embodiment may have a single casepackaged with a small variety of several types of membranes 110. In suchan embodiment, the user may purchase the packaged set, select themembrane 110 that suits the user's particular PDA, and install theselected membrane 110 with ease.

The protective cover of the present invention may have directconnections through the cover for connecting through the case. Such aconnection is known as pass through. The connections may be for power,communication, heat dissipation, optical transmissions, mechanicalmotion, or other reasons.

Electrical connections may require an insulated metal conductor from thePDA through the wall of the protective cover so that a flexible cablemay be attached or so that the PDA in its protective case may be placedin a cradle for making the electrical connection. Inside the protectivecover, the electrical connections may be made with a flexible cable thatis plugged into the PDAs electrical connector before the PDA is securedin the protective cover. Alternatively, a fixed connector may beattached to the protective cover and the PDA is slid into contact withthe fixed connector. Another embodiment may be for a compliant, yetfixed mounted electrical connector to be rigidly mounted inside theprotective cover. A compliant, yet fixed mounted electrical connectormay comprise spring loaded probes, commonly referred to as pogo pins.Another embodiment may comprise spring fingers that engage the PDAselectrical contacts. On the outside of the protective cover, theelectrical contacts may be terminated into a fix-mounted connectoradapted to receive a cable from a computer. The connector may bedesigned to receive a cable that plugs directly into the PDA or it maybe adapted to receive a different connector. Further, the electricalconnection to the PDA may be permanently attached to a cable thatextends out of the protective cover. Another embodiment may be to have asmall trap door that opens in the protective cover to allow access tothe electrical connections. While the trap door exposes the PDA to theelements the cover is designed to protect against, a direct electricalconnection may eliminate a potential cabling connection problem.Connections for fiber optics can be handled in similar fashions as theelectrical connections. An embodiment with a power connection maycomprise the use of inductive coils located in proximity to each otherbut on opposite sides of the protective cover. Those skilled in the artof may devise other embodiments for connecting through the protectivecover without deviating from the scope and intent of the presentinvention.

Through the air communications, such as infrared and over the air radiofrequency (RF) communications may pass through the protective cover. Thematerial for the front case 102 and rear case 104 may be selected to beclear plastic, such as polycarbonate. The infrared transceiver of thePDA can communicate through a clear plastic case to another infraredtransceiver outside of the case. Further, the appropriate selection ofmaterial for the protective case can thereby enable various RFtransmissions, such as cellular phone communications or other wirelesscommunication protocols.

An infrared transmission through the protective case of an embodiment ofthe invention may be accomplished by making the entire protective caseout of a clear material. Alternatively, a selected area of theprotective case may be clear while the remainder of the case is opaque.The selected area may be constructed of a separate piece that allows theinfrared light through the protective case. Alternatively, the selectedarea may be constructed of a portion of the protective case thatmanufactured in a way so as not to be opaque, such as selectively notpainting or plating the area of a plastic protective case. Further, theclear material through which the transmission occurs may be tinted inthe visual spectrum but be translucent or at least partially transparentin the infrared spectrum of the device.

A protective case may allow RF transmissions to and from the PDA whilethe case is closed. Such a case may be constructed of a non-metallicmaterial. In some embodiments, the material of the protective case maybe tuned to allow certain frequencies to pass through the protectivecover and tune out other frequencies, through loading the material usedin the protective cover with conductive media or through varying thethickness of the case and other geometries of the case in the area ofthe PDA transmission and reception antenna.

In a different embodiment, it may be desirable to shield the PDA fromoutside RF interference. In this case, the protective cover may be ametallic construction or may be plastic with a metallized coating.Further, membrane 110 may have a light metallized coating applied sothat membrane 110 is slightly or fully conductive. An application forsuch an embodiment may be the use of the PDA in an area of high RF noisethat may interfere with the operation of the PDA, or conversely, the usemay be in an area that is highly susceptible to external RF interferenceand the PDAs RF noise may be interfering with some other device.

The PDA may be equipped with a camera or other video capture device. Aprotective cover may have provisions to allow a clear image to be seenby the video capture device through the case. Such provisions mayinclude an optically clear insert assembled into the protective case.Other embodiments may have a sliding trap door whereby the user of thePDA may slide the door open for the camera to see. Additionally, otherembodiments may comprise a molded case that has an optically clear lensintegrally molded. Such an embodiment may be additionally painted,plated, or overmolded, with the lens area masked so that the painting,plating, or overmolding does not interfere with the optics of the lens.

An optically clear area may be used for a barcode scanner portion of aPDA to scan through the case to the outside world. In such anembodiment, a barcode scanner may be protected from the elements whilestill maintaining full functionality in the outside world.

The PDA may have indicator lights that indicate various items, such aspower, battery condition, communication, and other status items. Theindicator lights may be in positions on the PDA that are not readilyviewable through the protective membrane 110. The indicator lights maybe made visible through the protective case by using light pipes thattransmit the light from the PDAs status light to the outside of theprotective case. Such light pipes may be constructed of clear or tintedplastic, or other translucent or semi-transparent material. The lightpipes may be formed as an integral feature to the protective case or maybe separate parts that are formed separately and assembled to theprotective case.

The PDA may have a speaker or other element that makes noise and/or thePDA may have a microphone for receiving audio signals. The speaker maybe an audio quality device for reproducing sound or it may be a simplebuzzer for indicating various functions of the PDA. The microphone maybe an audio quality device or it may be a low performance device.Special provisions may be made for transmitting sound through aprotective case. Such provisions may range from a single hole in thecase to a tuned cavity that would allow sound to pass through withminimum distortion. Other embodiments may include a transmissivemembrane adapted to allow sound to pass through the protective case witha minimum of distortion. Such membranes may be located near the speakerand microphone elements of the PDA. Such membranes may be watertightmembranes known by the brand name Gore-Tex.

The PDA may generate heat during its use and provisions for dissipatingthe heat may be built into the protective cover. A heat-dissipatingdevice may be integral to the protective cover or may comprise one ormore separate parts. For example, a metallic protective cover may beadapted to touch the PDA in the area of heat generation and conduct theheat outwardly to the rest of the protective cover. The protective covermay thereby dissipate the heat to the external air without overheatingthe PDA. In another example, a separate heat sink may be applied to thePDA and allowed to protrude through a hole in the protective cover. Theheat sink may thereby transfer the heat from the PDA to the ambientenvironment without overheating the PDA. The heat sinks may be attachedto the PDA with a thermally conductive adhesive. Other embodiments mayinclude vent holes for heat dissipation and air circulation.

The PDA may have a button that may not be located underneath themembrane 110. An embodiment may include a flexible, pliable, orotherwise movable mechanism that may transmit mechanical motion from theoutside of the case to a button on the PDA. Such an embodiment may havea molded dimpled surface that is pliable and allows a user to activate abutton on a PDA by pressing the dimpled surface. Another embodiment mayhave a rigid plunger that is mounted on a spring and adapted to transmitthe mechanical movement from the exterior of the case to a button on thePDA. The buttons on the PDA may be located on any side of the PDA and anembodiment of a case may have pliable areas adapted to allow the user topress buttons that are not on the front face of the PDA.

FIG. 8 is an illustration of embodiment 800 of the present inventionwherein the PDA 802 is encapsulated by a protective cover 804. Theinstallation of the PDA 802 is to slide PDA 802 into the opening 808,then fold door 806 closed and secure with flap 810, which is hingedalong line 812. Areas 814 and 816 may comprise a hook and loop fastenersystem or other fastening device. Recessed area 818 is adapted to fitagainst touch screen 820 of PDA 802.

Embodiment 800 may be comprised of a single molded plastic part that maybe very low cost. As shown, embodiment 800 may not be completelyweathertight, since the door 806 does not completely seal the enclosure.However, such an embodiment may afford considerable protection to thePDA 802 in the areas of dust protection, scratch protection, and beingoccasionally rained upon. Further, the low cost of the embodiment 800may be changed often during the life of the PDA 802.

Embodiment 800 may have custom colors, logos, or designs that allow auser to personalize their PDA with a specific cover that is suited totheir mood or tastes. The colors, logos, and designs may be integrallymolded into the cover 804. Alternatively, different colors, logos, anddesigns may be applied in a secondary operation such as printing,painting, plating, or other application process.

FIG. 9 is an illustration of embodiment 900 of the present inventionwherein a decorative cover 902 is snapped over a PDA 904. The ends 906and 908 snap over the PDA ends 910 and 912 as an attachment mechanismfor cover 902 to PDA 904. Recessed area 914 is adapted to fit againsttouch screen 916

Embodiment 900 may be a cover for decorative purposes only, or may befor protective purposes as well. Cover 902 may be emblazoned with logos,designs, or other visual embellishments to personalize the PDA 904. Thecolors, logos, and designs may be integrally molded into the cover 904.Alternatively, different colors, logos, and designs may be applied in asecondary operation such as printing, painting, plating, or otherapplication process.

Embodiment 900 may be attached by snapping the cover 902 onto PDA 904.Special provisions in the case of PDA 904 may be provided for a snappingfeature of cover 902, or cover 902 may be adapted to hold onto PDA 904without the use of special features in PDA 904.

The features used to secure cover 902 to PDA 904 may be any mechanismwhereby the cover 902 can be secured. This includes snapping, clamping,fastening, sliding, gluing, adhering, or any other method for securingtwo components together.

FIG. 10 illustrates a perspective view of an embodiment of a receiver1002 for holding the protective case 100. The protective case 100 isheld into receiver 1002 in such a manner that the touch screen displayis facing into the receiver 1002, to afford the touch screen displaywith protection.

FIG. 11 illustrates a perspective view of the embodiment of a receiver1002 shown from the opposite side as FIG. 10. Receiver 1002 is comprisedof a back 1102, a belt clip mechanism 1104, and four clip areas 1106,1108, 1110, and 1112. The protective case 100 is placed into thereceiver 1002 by inserting one end into the receiver, then rotating theprotective case 100 into position such that the snapping action of clipareas 1106, 1108, 1110, and 1112 are engaged to hold protective case 100securely.

Receiver 1002 may be adapted to clip onto a person's belt or may beadapted to be mounted on a wall or other location where the PDA may bestored. The orientation of the protective case 100 is such that thetouch screen element of the PDA is protected during normal transport andstorage, since the touch screen interface is facing the back 1102 of thereceiver 1002.

Receiver 1002 may be made of compliant plastic that allows the clipareas 1106, 1108, 1110, and 1112 to move out of the way and spring backduring insertion or removal of the protective case 100. In the presentembodiment, receiver 1002 may be constructed of a single part. Inalternative embodiments, receiver 1002 may be constructed of multipleparts and of multiple materials, such as a metal back with spring loadedclips. In other embodiments, special features may be included in theprotective case 100 where the receiver 1002 may engage a special featurefor securing the protective case 100.

FIG. 12 illustrates an embodiment 1200 of the present invention of aprotective cover for a PDA or other device. A rigid front cover 1202 anda rigid rear cover 1204 are held together with a series of latches 1206,1208, 1210, and 1212. The protective membrane 1214 protects thetouchscreen of the enclosed PDA. A folding rigid cover 1216 operates asa rigid shield to prevent the membrane 1214 from any damage. The stylusholder 1220 is formed from an overmolded flexible material in which themembrane 1214 is mounted.

Embodiment 1200 illustrates yet another embodiment of the presentinvention wherein a rigid protective cover may be used to contain andprotect an electronic device, but provide full usable access to atouchscreen. The protective membrane 1214 and case may be watertight insome embodiments.

FIG. 13A illustrates an embodiment of a protective enclosure 1300 thatencloses and protects a tablet PC 1302. PDAs that have touch screens, asdescribed above, have an interactive flat-panel control, i.e., the touchscreen display. Tablet PCs are portable electronic computing devicesthat have a high-resolution interactive flat-panel control that acceptssmooth stylus strokes such as handwriting. The embodiment of FIG. 13A iscrush-resistant, impact-resistant, watertight, and simultaneously allowsinteractive stylus strokes and other sensitive user inputs to beaccurately and easily transmitted through a protective screen membrane1306 to the interactive flat-panel control of tablet PC 1302.

A watertight and shock-absorbing foam cushion 1310 may be fixed andsealed to the underside of the lid 1304 around the interactiveflat-panel control opening. The protective screen membrane 1306 is fixedand sealed to the shock-absorbing foam cushion 1310. The shock-absorbingfoam cushion 1310 maintains the watertightness of the enclosure. Thecushion 1310 also cushions the flat-panel control of the tablet PC 1302and protects it against breakage if the enclosure and tablet PC aredropped or otherwise subjected to shock. In accordance with theembodiment of FIG. 13A, the shock-absorbing foam cushion 1310 has athickness of approximately 0.25 inches and extends approximately 0.060inches below the underside of the interactive flat-panel control openingof the lid 1304. One source of suitable watertight shock-absorbing foamis E.A.R. Specialty Composites of 7911 Zionville Rd., Indianapolis, Ind.46268. Cushion 1310 allows the protective screen membrane to move adistance of up to 0.125 inches during an impact to the enclosure or whenpressure is applied to protect membrane 1306 while pushing the tablet PCcontrol buttons 1308 or writing on the interactive flat-panel controlwith a stylus through the membrane. The shock-absorbing foam cushion1310 also pushes the protective screen membrane 1306 flatly against thesurface of the interactive flat-panel control of the tablet PC 1302 sothat sensitive user stylus strokes and other inputs are accuratelytransmitted. The pressure of the cushion 1310 on the protective screenmembrane 1306 which holds the protective screen membrane 1306 flatlyagainst the interactive flat-panel control of the tablet PC 1302 alsokeeps display images, viewed through the protective screen membrane,clear and distortion-free. In embodiments of the protective enclosure toprotect a touch-screen device, the protective membrane may be adjacentto the touch screen but does not exert mechanical pressure on the touchscreen so that mechanical inputs such as style strokes are sensed onlywhen intended. In embodiments of the protective enclosure to protect atablet PC that has an RF stylus or to protect a handheld device that acapacitance-sensing interactive flat-panel control, the protectivemembrane may be pressed flat against the interactive flat-panel controlwhich allows undistorted viewing but does not adversely affect thecontrol since the interactive control uses capacitance or radiofrequencies for interactive input instead of mechanical pressure.

The protective screen membrane 1306 in the embodiment of FIG. 13A is atleast partially transparent and has a thickness of approximately 0.010inches. The thickness of the protective screen membrane 1306 should betypically in the range of 0.001 inches to 0.020 inches so that stylusstrokes on the upper surface of protective screen membrane 1306 aretransmitted accurately to the interactive flat-panel control of thetablet PC 1302. Likewise, protective screen membrane 1306 may beflexible or semi-rigid and may be made of polyvinylchloride or othersuitable transparent thermoplastic, such as, for example,polyvinylchloride, thermoplastic polycarbonate, thermoplasticpolypropylene, thermoplastic acrylonitrile-butadiene-styrene,thermoplastic polyurethane, which has a hardness and texture thatpermits the stylus to smoothly glide across the surface withoutskipping, grabbing, or catching against the surface. Some tablet PC'sutilize a stylus which transmits strokes to the PC by way of radiofrequency transmission. Protective screen membrane 1306 may be made of arigid, clear, engineered thermoplastic such as, for example,thermoplastic polycarbonate or other thermoplastics as described above,for enclosing a tablet PC. A protective screen membrane 1306 that isrigid may include watertight access ports that allow operation ofmechanical buttons or switches of the tablet PC 1302, such as, forexample, control buttons 1308. The watertight access ports may includeholes that have a moveable watertight plug, or any type of watertightbutton or lever. Protective screen membrane 1306 may include ananti-glare coating or can be made with an anti-glare texture so thatdisplay images are clearly viewable without distortion through theprotective screen membrane 1306.

In the embodiment of FIG. 13A, the lid 1304 of the protective enclosure1300 may have an external stylus holder 1324 that securely holds astylus used with the tablet PC 1302.

As described above with respect to FIG. 1, the lid 1304 and the base1312 may have air-permeable watertight vents 1318, 1326 that permit thecooling fans of the tablet PC 1302 to force air exchange to dissipateheat by convection so that the tablet PC 1302 does not overheat.Watertight vents 1318, 1326 may comprise holes in the lid 1304 and base1312 that are made watertight by covering and sealing the holes with anair-permeable watertight membrane such as, for example, a fabricatedexpanded polytetrafluoroethylene (ePTFE) membrane. One source thatfabricated expanded polytetrafluoroethylene (ePTFE) membranes isavailable from is W. L. Gore & Associates, Inc. of 555 Papermill Road,Newark, Del. 19711.

The embodiment of FIG. 13A may also comprise a pod door 1322 that allowsaccess to table PC interfaces such as, for example, PCMCIA or Smart Cardslots. The pod door 1322 is attached to the lid 1304 so that it may beremoved or opened. In the embodiment of FIG. 13A, the pod door 1322 ishingedly connected to a portion of the base 1312 at a location of thebase 1312 that has an opening that allows access to the tablet PCinterfaces. The opening can be covered by a watertight seal 1320, suchas, for example, an O-ring that is part of pod door 1322.

The underside of the lid 1304 also has a watertight seal, such as anO-ring, so that when compound latches 1328, 1330, 1332 and 1334 areclosed, the O-ring or seal of the lid 1304 forms a watertight sealagainst the base 1312. The protective enclosure 1300 protects the tabletPC 1302 from water and dust intrusion sufficient to comply with IngressProtection (IP) rating of IP 67, i.e., the protective enclosure totallyprotects the enclosed tablet PC from dust and protects the enclosedtablet PC from the effects of immersion in one meter of water for 30minutes.

The protective enclosure of the embodiment of FIG. 13A may furthercomprise protective overmolding 1316 attached to the lid 1304. A similarovermolding may be attached to the base 1312. The protective overmolding1316 may be made of material that is easily gripped in slipperyconditions and provides additional shock absorption such as, forexample, rubber or silicone. The protective overmolding 1316 extendsabove the surface of the lid in pre-determined areas to provideprotrusions that are easily gripped even in slippery conditions. Theprotective enclosure of the embodiment of FIG. 13 may further comprisewatertight plugs such as access port plug 1314 that fit snugly intoopenings in the base 1312 that provide access to various interfaces,connecters and slots of the tablet PC 1302.

FIG. 13B illustrates a shell lid 1304 of the embodiment of FIG. 13A.Shell lid 1304 and base 1312 may be made of impact/crush resistantmaterial such as glass-fiber reinforced engineered thermoplastic, suchas for example, glass reinforced polycarbonate. Alternatively, the shelllid 1304 and shell base may be made of thermoplastic polycarbonate,thermoplastic polypropylene, thermoplasticacrylonitrile-butadiene-styrene, and thermoplastic compositionscontaining one or more thereof, or other engineered thermoplastics thatprovide a shock-resistant and impact resistant shell may be used. Theengineered thermoplastics may be reinforced with glass fibers, carbonfibers, metal fibers, polyamide fibers and mixtures thereof. Shell lid1304 may be further reinforced with stiffeners 1334, 1336, 1338, 1340that are integrally embedded into the shell lid around the perimeter ofan opening in the shell that is directly over the interactive flat-panelcontrol portion of the tablet PC. The stiffeners made be made of steelor other hard material so that the stiffeners provide additionalstrength and prevent flexing of the lid 1304 which enhances thewatertightness and the impact/crush resistance.

FIG. 14 is an illustration of the embodiment of FIG. 13A with the lid1404 detached from the base 1412. To protect the tablet PC 1402 usingthe protective enclosure 1400, the tablet PC 1402 is disposed to fitsnugly into the base 1412. The lid is oriented so that hooks 1436, 1438area aligned with pin 1440 that is connected to a portion of the base1412 and the lid is closed so that hooks 1436, 1438 are retained by pin1440. Compound latches 1428, 1430, 1432, 1434 are then snapped onto thelid so that the lid is compressed tightly against the base providing awatertight seal.

FIG. 15 is a bottom view of the embodiment of FIG. 13. The base 1516 ofprotective enclosure 1500 includes watertight vents such as watertightvent 1506 for air exchange to permit heat and sound dissipation from theenclosed tablet PC while at the same time maintaining watertightness.

Pod release knobs 1512, 1518 are attached to the base 1516 so that theknobs can be rotated clockwise to securely wedge against an edge of poddoor 1522 to close the pod door 1522 tightly against a rim around an thepod opening in base 1516 to create a watertight seal. Knobs 1512, 1518can be rotated counter-clockwise to release pod door 1522 to access theinterfaces of the tablet PC covered by pod door 1522.

To provide additional protection against mechanical shock, heavy-dutycorner bumpers such as bumper 1504 may be securely attached to thecorners of base 1516.

As shown in FIG. 15, an adjustable heavy-duty handle may be attached tothe base 1516 of the protective enclosure 1500 to allow easy andreliable transportation of the protective enclosure 1500 that encloses atablet PC. In some circumstances, it is convenient to hold theprotective enclosure using hand strap 1514 that is made of strongslightly stretchable fabric. Hand strap 1514 attaches to four points ofthe base 1516 to that a user's hand or wrist can be inserted along theeither the longer or shorted length on the protective enclosure 1500 andenclosure tablet PC. Hand strap 1514 may be made of neoprene or otherstrong stretchable material to securely hold the protective enclosure tothe user's arm even in slippery conditions. The protective enclosure mayfurther include a neck strap to provide a comfortable solution for usingthe tablet PC while standing.

FIG. 16 illustrates a top view of the protective enclosure base 1600.Watertight vents such as watertight vent 1616 allow air exchange forheat dissipation and sound transmission from an enclosed tablet PC. Sealrim 1614 is an integrally formed part of the protective enclosure 1600which is compressed against an O-ring in the protective enclosure lid toprovide a watertight seal when compound latches 1628, 1630, 1632, 1634are closed onto the lid.

Internal bumpers 1602, 1604, 1608, 1610 attach to the interior cornersof protective enclosure base 1600 to provide cushion and mechanicalshock protection to an enclosed tablet PC. The L-shape and non-solidinterior of internal bumpers 1602, 1604, 1608, 1610 allows the bumpersto deflect and absorb the shock if the enclosed tablet PC is dropped orotherwise subjected to mechanical shock. The protective enclosureprovides shock absorption sufficient to meet MIL-STD 810F, Method 516.5,Procedure 4 which is a Transit Drop Test. In the Transit Drop Test, theprotective enclosure encloses a tablet PC or a mass equivalent to atablet PC. The protective enclosure is sequentially dropped onto eachface, edge and corner for a total of 26 drops over plywood from a heightof 48 inches. The protective enclosure is visually inspected after eachdrop and a functional check for leakage is performed after all drops arecompleted.

Some tablet PCs have a docking connector disposed on the underside ofthe tablet PC so that the tablet PC can connect to power and signals.For example, emergency vehicles such as ambulances, fire trucks, orpatrol cars, may have a docking station installed near the driver's seatonto which the driver may dock a tablet PC. The embodiment of protectiveenclosure base 1600, as illustrated in FIG. 1, may comprise a dockingconnector channel 1624 that is recessed with respect to the uppersurface of the base that allows a docking connector to run from adocking connector that is disposed in the center underside of the tabletPC to access port 1626. Alternatively, a docking pass-through connector1620 may be made an integral and watertight part of the protectiveenclosure base 1600 so that the tablet PC docking connector attaches tothe docking pass-through connector 1620 which, in turn, connects to thedocking station in substantially the same manner as an unenclosed tabletPC.

FIG. 17 illustrates another embodiment of protective enclosure 1700 fora handheld electronic device 1702 that has an interactive flat-panelcontrol. Handheld electronic devices that have an interactive flat-panelcontrol benefit from being enclosed in a rugged protective enclosurethat is crush-resistant, watertight and shock-resistant and thatsimultaneously allows the user to interact with a sensitive interactiveflat-panel control. Handheld electronic devices that have interactiveflat-panel control may include music players, MP3 players, audioplayer/recorders, and video players. For example, Apple Computer Ipod isa popular handheld interactive device that plays MP3 or otherwisedigitally-encoded music/audio. The Apple Ipod has an interactiveflat-panel control in which a portion of the front panel is a flat-paneldisplay and portion of the front panel is an interactive flat-panelcontrol, called a touch wheel in some versions of the Ipod and clickwheel in other versions of the Ipod, that has capacitive touch/proximitysensors. One function of the interactive flat-panel control, i.e. touchwheel, emulates a rotary control knob by sensing circular motion of auser's finger using capacitive sensors. The click wheel has the samefunction with the additional feature of sensing proximity of a user'sfinger and emulating button presses by a user's finger at pre-determinedareas.

In the embodiment of FIG. 17, the shell lid 1706 and the shell base 1704are made of polycarbonate or other engineered thermoplastics that arecrush-resistant and impact resistant. Shell base 1704 has a watertightseal 1718, which may be an overmolded gasket, o-ring, liner or otherseal that prevents water from entering the protective enclosure 1700when the handheld interactive device 1702 is enclosed inside theprotective enclosure 1700. Shell base 1704 and shell lid 1706 mayinclude watertight vents, electrical connectors, see-through areas orfeatures as disclosed with respect to FIG. 1.

In the embodiment of FIG. 17, shell lid 1706 includes apertures overpredetermined portions of the handheld interactive device 1702, such asthe areas directly over the display screen 1714 and the interactiveflat-panel control 1712, or other designated areas as desired. Aprotective screen membrane 1710 that is at least partially transparentis permanently or removably fixed in a watertight manner to theunderside of shell lid 1706 in the aperture that is over the displayscreen 1714. The protective screen membrane 1710 is recessed withrespect to the upper surface of the shell lid 1706 which providesprotective elevated rim that protects the display screen 1714 frombreakage. Protective screen membrane 1710 may be PVC, silicone or othermaterial that is watertight and rugged. In the case that display screen1714 is a touch screen, the protective screen membrane 1710 should besmooth enough and thin enough that stylus strokes and other inputs aretransmitted accurately to the touch screen as disclosed above withrespect to FIG. 1, FIG. 12, and FIG. 13.

In accordance with the embodiment of FIG. 17, a protective controlmembrane 1708 is permanently or removably fixed in a watertight mannerto the underside of shell lid 1706 in an aperture that is over theinteractive flat-panel control 1714 of the handheld device 1702. Theprotective screen membrane 1710 is recessed with respect to the uppersurface of the shell lid 1706 which provides protective elevated rimthat protects the display screen 1714 from breakage and provides tactilefeedback that guides a user's finger to the desired area even inslippery conditions.

Interactive flat-panel control 1712 has capacitive sensors which arepart of a proximity/touch detector circuit. When a grounded object, suchas a person's finger, which has free air capacitance of several hundredpicofarads, is brought close to the capacitive sensors, the totalcapacitance measured by the detector circuit increases because thecapacitance of the object with free air capacitance adds to thecapacitance of the sensors since the total capacitance of two capacitorsin parallel is additive. Multiple sensors may also be arranged so thatmovement of an object with free air capacitance can be detected, forexample, movement of a person's finger in a circular motion analogous toturning a mechanical control knob. Some examples of interactiveflat-panel controlled PDA's include Ipod and Ipod Mini music and audioplayers from Apple Computer. In some PDAs, such as the Apple Ipod,capacitive sensors may be disposed below a front panel made from adielectric such as polycarbonate which has a dielectric constant in therange of 2.2-3.8. In the embodiment of FIG. 17, the protective controlmembrane 1708 is made of thin polycarbonate that is slightly flexible orother engineered thermoplastics that provide the rugged watertightprotection and at the same time permit the capacitive sensors of theinteractive flat-panel control 1712 to function correctly. Likewise, aprotective control membrane 1708 with a dielectric constant that is toohigh may retain an electric charge long enough to reduce the responserate of the sensor to motion of a user's finger from one capacitivesensor zone of the interactive flat-panel control 1712 to another. Aprotective control membrane 1708 that is conductive or has a dielectricconstant that is too low may diminish the sensitivity of the capacitivesensor by combining in series the capacitance of the protective membraneand the dielectric front panel of the PDA which results in a lowering ofthe overall capacitance.

Total capacitance between an object, such as a finger touching theprotective control membrane 1708, and interactive flat-panel control1712 is a function of the thickness and the dielectric constant of theprotective control membrane 1708. The capacitance between the object,such as a finger, and the capacitive sensors of the interactiveflat-panel control 1712 is proportional to the distance between theobject and the sensors. The sensitivity of the capacitive sensors to theobject may be diminished or completely eliminated if the protectivecontrol membrane 1708 is too thick. In the embodiment of FIG. 17, thethickness of the protective control membrane is approximately 0.020inches. The protective control membrane 1708 may be any thickness in therange of 0.003 inches to 0.020 inches that is adequate to provide arugged watertight membrane through which capacitance can be correctlysensed by the interactive flat-panel control 1712.

The upper surface of the protective control membrane 1708 has avelvet/matte texture with a texture depth of 0.0004 to 0.003 inches thatreduces the surface area of the membrane that is in frictional contactwith the user's finger and permits a user's finger to glide rapidly uponthe surface of the membrane without catching or sticking as a result ofthe reduced friction. The hardness of the polycarbonate material, orother hard engineered thermoplastic, also reduces the friction.

Headphones or other accessories may be electrically connected tohandheld device 1702 the through the protective enclosure 1700 bydisposing the wire of the headphone or accessory in an insertable gasket1716 which fits snugly into one end of the shell base 1704.

FIG. 18 illustrates another embodiment of protective enclosure 1800which is substantially the same as protective enclosure 1700 of FIG. 17.However, protective enclosure 1800 has an alternative electricalpass-through for accessories. In the embodiment of FIG. 18, shell base1804 includes an adapter cable 1816 that has an adapter plug 1812 at oneend which plugs into a jack of handheld device 1802. At the other end ofthe adapter cable 1816 is an adapter jack 1814 that is molded into, orotherwise integrally made part of, shell base 1804. An externalaccessory, such as a pair of headphones, may then be plugged into theadapter jack 1814 while the handheld device 1802 in enclosed inprotective enclosure 1800. Alternatively, a one-piece adapter thatincludes both a jack 1814 and a plug 1812 without a cable 1816 may beintegrally disposed into shell base 1804.

Shell lid 1806 is adapted to retain an O-ring 1808 that seals theprotective enclosure 1800 when shell lid 1806 is latched tightly ontoshell base 1804 so that water cannot enter protective enclosure 1800.

The foregoing description of the invention has been presented forpurposes of illustration and description. It is not intended to beexhaustive or to limit the invention to the precise form disclosed, andother modifications and variations may be possible in light of the aboveteachings. The embodiment was chosen and described in order to bestexplain the principles of the invention and its practical application tothereby enable others skilled in the art to best utilize the inventionin various embodiments and various modifications as are suited to theparticular use contemplated. It is intended that the appended claims beconstrued to include other alternative embodiments of the inventionexcept insofar as limited by the prior art.

1. A protective enclosure for a tablet PC having an interactiveflat-panel control comprising: a shell that is capable of enclosing saidtablet PC, said tablet PC being a separate unit from said protectiveenclosure, said tablet PC being insertable in and removable from saidenclosure by hand, said shell being substantially crush-resistant andhaving an elevated protective rim around a perimeter portion of saidinteractive flat-panel control of said tablet PC so that when saidtablet PC is disposed in said enclosure, said interactive flat-panelcontrol of said tablet PC is recessed with respect to said protectiverim of said shell so that said elevated protective rim protects saidinteractive flat-panel control from breakage; and a protective membranethat is integrally fixed to a shock-absorbing cushion, saidshock-absorbing cushion being fixed to said shell, said shock-absorbingcushion forming a seal between said shell and said protective membraneso that said protective enclosure is substantially watertight, saidprotective membrane is disposed over said interactive flat-panel controlof said tablet PC when said tablet PC is disposed in said enclosure,said protective membrane having a back side that has a substantiallyplanar smooth surface that is adjacent to said interactive flat-panelcontrol of said tablet when said tablet PC is disposed in said enclosureso that inputs on a front side of said protective membrane arecommunicated to said interactive flat-panel control through saidprotective membrane, said protective membrane being at least partiallytransparent such that said interactive flat-panel control is visiblethrough said protective membrane, said shock-absorbing cushion pressingsaid protective membrane flatly against said interactive flat-panelcontrol of said tablet PC so that smooth stylus strokes and inputs maybe transmitted accurately to said interactive flat-panel control.
 2. Theprotective enclosure of claim 1 further comprising a plurality ofshock-absorbing bumpers that are attached to said shell of saidprotective enclosure, said bumpers being adapted to hold said tablet PCsnugly, said bumpers being compressible so that when said tablet PC isdisposed in said protective enclosure said tablet PC is substantiallyprotected from mechanical shock to said protective enclosure, saidbumpers sized and disposed within said protective enclosure so that airmay flow around said tablet PC within said protective enclosure.
 3. Theprotective enclosure of claim 1 further comprising at least oneair-permeable watertight vent in said protective enclosure that permitsheat transfer by convection of heat generated by said tablet PC from theinterior of said protective enclosure to the exterior of said protectiveenclosure so that said tablet PC operates with sufficient cooling. 4.The protective enclosure of claim 1 wherein said shell of saidprotective enclosure further comprises grip-enhancing structures thatenable said protective enclosure to be securely held by hand in slipperyconditions.
 5. The protective enclosure of claim 1 wherein saidprotective enclosure uses at least one latch to securely close saidenclosure around said tablet PC.
 6. The protective enclosure of claim 1further comprising glare-reducing coating on a front side of saidprotective membrane.
 7. The protective enclosure of claim 1 wherein saidshell is made of at least one engineered thermoplastic selected from thegroup consisting of thermoplastic polycarbonate, thermoplasticpolypropylene, thermoplastic acrylonitrile-butadiene-styrene andthermoplastic compositions containing one or more thereof.
 8. Theprotective enclosure of claim 7 wherein said shell is reinforced with atleast one fiber material selected from the group consisting of glassfibers, carbon fibers, metal fibers, polyamide fibers and mixturesthereof.
 9. The protective enclosure of claim 8 wherein said shellfurther comprises stiffeners that are embedded in a perimeter thatsurrounds said protective membrane of said shell so that said stiffenersstrengthen said shell and prevent said shell from warping.
 10. Theprotective enclosure of claim 9 wherein said protective membrane isfabricated from a member of the group consisting of polyvinylchloride,thermoplastic polycarbonate, thermoplastic polypropylene, thermoplasticacrylonitrile-butadiene-styrene, thermoplastic polyurethane, andthermoplastic compositions containing one or more thereof.
 11. Aprotective enclosure for a handheld device having a capacitance-sensinginteractive flat-panel control comprising: a shell that is capable ofenclosing said handheld device, said handheld device being a separateunit from said protective enclosure, said handheld device beinginsertable in and removable from said enclosure by hand, said shellbeing substantially crush-resistant and having an elevated protectiverim around a perimeter portion of said capacitance-sensing interactiveflat-panel control of said handheld device so that when said handhelddevice is disposed in said enclosure, said capacitance-sensinginteractive flat-panel controlled device of said tablet is recessed withrespect to said protective rim of said shell so that said elevatedprotective rim protects said interactive flat-panel control frombreakage; and a protective membrane that is integrally fixed to saidshell, said protective membrane disposed over said capacitance-sensinginteractive flat-panel control of said handheld device when saidhandheld device is disposed in said enclosure, said protective membranehaving a back side that has a substantially planar smooth surface thatis adjacent to said capacitance-sensing interactive flat-panel controlof said handheld device when said handheld device is disposed in saidenclosure, said protective membrane being sufficiently thin thatcapacitive inputs on a front side of said protective membrane aretransmitted to said capacitive-sensing interactive flat-panel controlthrough said protective membrane, said protective membrane being atleast partially transparent such that said interactive flat-panelcontrol is visible through said protective membrane, said protectivemembrane having a dielectric constant such that capacitive inputs on afront side of said protective membrane are transmitted to saidcapacitance-sensing interactive flat-panel control.
 12. The protectiveenclosure of claim 11 wherein said protective membrane has a dielectricconstant in the range of 2.2 to 3.8.
 13. The protective membrane ofclaim 12 wherein said protective membrane is made of engineeredthermoplastic selected from the group consisting of thermoplasticpolycarbonate, thermoplastic polypropylene, thermoplasticacrylonitrile-butadiene-styrene and thermoplastic compositionscontaining one or more thereof.
 14. The protective enclosure of claim 13wherein said protective membrane has a thickness in the range of 0.003inches to 0.020 inches.
 15. The protective enclosure of claim 14 whereinsaid protective membrane has matte texture, said texture having atexture depth of 0.0004 to 0.003 inches that reduces the surface area ofsaid protective membrane that is in frictional contact with a user'sfinger and permits said user's finger to glide smoothly upon the surfaceof the membrane without sticking.
 16. A method of manufacturing aprotective enclosure for a device having an interactive flat-panelcontrol comprising: providing a protective shell that is crush resistantand impact resistant, said protective shell having embedded stiffenersthat prevent said protective shell from warping, said protective shellthat is adapted to enclose a device having an interactive flat-panelcontrol, said device being a separate unit from said protectiveenclosure, said device being insertable in and removable from said shellby hand, said shell being substantially crush-resistant and providing anelevated protective rim around a perimeter portion of said interactiveflat-panel control of said device so that when said device is disposedin said enclosure, said interactive flat-panel control is recessed withrespect to said protective rim of said shell so that said elevatedprotective rim protects said interactive flat-panel control of saiddevice from breakage; providing a protective membrane that is capable ofbeing integrally fixed on said shell so that said protective membrane isdisposed over said interactive flat-panel control of said device whensaid device is disposed in said enclosure, said protective membranehaving a back side that has a substantially planar smooth surfaceadjacent said interactive flat-panel control when said device isdisposed in said enclosure so that inputs on a front side of saidprotective membrane are communicated to said interactive flat-panelcontrol through said protective membrane, said protective membrane beingat least partially transparent such that said interactive flat-panelcontrol is visible through said protective membrane; and fixing saidprotective membrane onto said protective shell so that said protectivemembrane and said protective shell form a protective enclosure for saidtouch screen device.
 17. A method of manufacturing a protectiveenclosure for a device having a capacitance-sensing interactiveflat-panel control comprising: providing a protective shell that iscrush-resistant and impact-resistant, said protective shell that isadapted to enclose a device having a capacitance-sensing interactiveflat-panel control, said device being a separate unit from saidprotective enclosure, said device being insertable in and removable fromsaid shell by hand, said shell being substantially crush-resistant andproviding an elevated protective rim around a perimeter portion of saidcapacitance-sensing interactive flat-panel control of said device sothat when said device is disposed in said enclosure, saidcapacitance-sensing interactive flat-panel control is recessed withrespect to said protective rim of said shell so that said elevatedprotective rim protects said capacitance-sensing interactive flat-panelcontrol of said device from breakage; providing a protective membranethat is capable of being integrally fixed on said shell so that saidprotective membrane is disposed over said capacitance-sensinginteractive flat-panel control of said device when said device isdisposed in said enclosure, said protective membrane having a back sidethat has a substantially planar smooth surface adjacent said interactiveflat-panel control when said device is disposed in said enclosure, saidprotective membrane being sufficiently thin and having dielectricconstant so that capacitive inputs on a front side of said protectivemembrane are communicated to said capacitance-sensing interactiveflat-panel control through said protective membrane, said protectivemembrane being at least partially transparent such that saidcapacitance-sensing interactive flat-panel control is visible throughsaid protective membrane; and fixing said protective membrane onto saidprotective shell so that said protective membrane and said protectiveshell form a protective enclosure for said device.